How to calculate the tonnage required to stamp and form steel sheet at a punching press?

Question

How to calculate the tonnage required to stamp and form steel sheet at a punching press?

Answer 1

FOR CUTTING OPERTAION-CUTTING FORCE=PxTXFs

WHERE

P-PERIMETER

T=THICKNESS OF SHEET

Fs-SHEAR STRENGTH

TONNAGE-C.F+STRIPPING FORCE(20% OF C.F)

APX  CALCULATION  FORMING FORCE

(Y+U)/2 X A

Y=YIELD STRENGTH

U=ULTIMATE STRENGTH

A=AREA OF CROSS SECTION

Answer 2

This page has a load calculator (scroll down)

http://www.accurpress.com/pbrakes.html#l...

To me it didn't seem to require enough info but maybe it will help you out.